There are various adapters that allow using large (5# and larger) propane tanks on devices that use only the 1# bottles, and vice-versa. This allows using a 1LB cylinder on a large bbq, or a 20# on a lantern, etc. There are also adapters that allow using a propane cylinder on a classic Coleman stove (it replaces the tank/regulator, and fits inside the stove for storage).

All are highly recommended!

I may look into the one for the Coleman...I don't have a gas grill, just charcoal, so I don't have any 20# cylinders, just a bunch of the 1# ones.